Crowley was born in Pasadena, California and attended the University of Southern California between 1968 and 1976 where he graduated with a Bachelor of Music in Piano Performance/Composition and with a Master of Music in Orchestral Conduction. He then worked as teacher at Biola College and at the Dick Grove School of Music.

Crowley has started a career as announcer and voice performer in 1986 and is well known as voice of the documentary series E! True Hollywood Story (1997-2005) and the reality show Shar Tank (2009-2014). He was spokesman for brands such as Priceline, Verizon, Jaguar, Pepsi, Chevron, and Mercedes and narrated several documentaries for National Geographic, the Travel Channel, and the History Channel. Crowley also lent his voice for the television series TaleSpin (1991, with Mark L. Taylor), That 70's Show, and Sunset Beach, the comedy Dickie Roberts: Former Child Star (2003, with Kevin Grevioux and Spencer Garrett), the drama Shades of Gray (2009), and the comedy Movie 43 (2013, with Seth MacFarlane and Jimmy Bennett).

Crowley appeared for the first time as actor in front of the camera in the 2008 short film Seed for You. He also played in various stage plays including versions of "The Imaginary Invalid", "You Can't Take It With You", "The Mikado", "Teahouse of the August Moon", "HMS Pinafore", and "The Philadelphia Story".